Technical Abstract:
Irrigation scheduling can be greatly improved if accurate soil water content data are available. There are a plethora of available soil water sensing systems, but those that are practical for irrigation scheduling are divided into two major types: the frequency domain (capacitance) sensors and the time domain sensors. Several of each type of sensor were demonstrated to the public, and the performance, and usefulness of each sensor was discussed. The capacitance sensors were capable of showing patterns over time in soil wetting and drying but were incapable of reporting soil water content data accurately enough for irrigation scheduling. The time domain sensors, once too expensive and complicated for irrigation scheduling, were represented by two new, affordable and easy-to-use sensors from different manufacturers that use time domain measurement principles to deliver accurate water content, and soil temperature, and bulk electrical conductivity data that are very useful for irrigation scheduling.